In a transducer, energy of one form is converted to energy of a different form. Electroacoustic transducers convert electrical impulses to acoustic vibrations that may be perceived as audible sound to proximate listeners. Some such electroacoustic transducers are electromagnetic transducers driven electromagnetically by a drive unit comprising a permanent magnet and a voice coil having a plurality of wire windings. Here, electrical signals supplied to the voice coil generate a magnetic field that interacts with the magnetic field generated by the permanent magnet, inducing motion in the voice coil. As the voice coil is affixed to a diaphragm, this motion may be conveyed to the diaphragm to produce sound.